Escapement mechanism for timepieces.



P.H.O0RTHBLL ESG'APEMENT MECHANISM FOR TIMEPIEGES.

APPLICATION FILE-D NOV.16, 1913.

1 ,107A10, Y Patented Aug. 18, 19M

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a. 77% %QW%WT% THE NORRIS PETERS co. PHOTO-LITHOW WASHINGTON, u. 4:.

UNITED STATES ,PATEN T OFFICE.

FRED I-I. CORTHELL, OF CHICAGO, ILLINOIS, ASSIGNOR T0 EDNARD R. HILLS,OF

CHICAGO, ILLINOIS.

ESCAPEMENT MECHANISM FOR TIMEPIECES.

Specification of Letters Patent.

Patented Aug. 18, 1914.

Application. filed November 15, 1913. Serial No. 801,103.

To all whom it may concern Be'it known that I, FRED H. CORTHELL, acitizen of the .United States, residing at Chicago, in the county ofCook and State of Illinois, have invented certain new and. usefulImprovements in Escapement Mecha nisms for Timepieces, of which thefollowing is a specification.

This invention relates to escapement mechanisms for use in chronometers,both clocks and watches, and has for its main object to provide animproved mechanism of aun t type, that is, of that type wherem thevarious parts making up the complete escapement mechanism are capable ofapplication to and removal from the frame plate as a unit, and withoutdanger of injury to the driving wheel that meshes with. the escapepinion, or to other parts of the clockor watch train. These objects Iaccomplish in part through a construction which involves and requiresthe complete separation of the escape pinion from the driving wheelbefore the escapement mechanism can be removed, and in part bya devicewhich automatically locks the train against movement simultaneously withthe withdrawal of the escape pinion out of gear with the driving wheel.

My invention, its mode of operation, and its advantages will all bereadily understood when considered in connection with the ac companyingdrawings, in which I Figure 1 is a top plan view of a fragment of aclock-plate showing my improved escapement mechanism mounted thereon.Fig. 2 is a vertical section through the salmon the line 2-2 of Fig. 1;and Fig. 3 is a vertical section on the line 3-3 of Fig. 1.

1 Referring to the drawings, 5 designates the clock-plate, or anequivalent member of the frame of a watch movement, through which isformed an approximately circular slot 6 to accommodate the potence 7.The circular slot 6 is formed with an approximately semi-circularextension 8 of reduced diameter on one side thereof that accommodatesthe inner or neck portion of the potence; and the portion of theclock-plate around the extension 8 is cut away or coun-' tersunk on itsunder side as indicated at 9 to fit a narrowed segment 7 of the circularmain or body portion of the potence, which segment forms a lockingshoulder.

The escapement mechanism, which is of the usual construction, comprisesthe escapement plate 10, the escape wheel bridge 11 secured to theescapement plate by a screw 12, the balance bridge 13 also secured tothe escapement plate 10 by a screw 1 1, the balance wheel 15- journaledbetween the balance bridge and the escapement plate, the escape wheel 16on the escape arbor 17 this latter journaled between the escape wheelbridge 11 and the lower end of the potence 7, and carrying the escapepinion 18, the potence 7 secured to the under side of the escapementplate 10 by the screw 19, the pal let bridge 20, and the pallet 21journaled between the pallet bridge and the escapement plate; the entireescapement mechanism comprising the parts specified and their variousbearings being secured to the clock-plate 5 by the screw 22. A123 isshown a fragment of the driving wheel which, as is well understood, isjournaled on the under side of the clock-plate 5, and drivingly engagesthe escape pinion 18.

The drawings show the parts in their assembled and operative positionand relation. To remove the escapement mechanism, when required forcleaning, repairs, or otherpurposes, it is necessary only to withdrawthe fastening screw 22, then push the entire mechanism to the left asshown in Figs. 1 and 2, by which the locking shoulder 7 is 'withdrawnfrom the countersink 9 of the clock-plate and shifted into register withthe main circular portion of the slot 6 of the clock-plate, whereuponthe potence can be bodily lifted entire through said main circular slot.This operation involves the complete separation of the escape pinion 18from the driving wheel 23-before the. mechanism is raised from theclock-plate, and likewise insures that the lower end of the potenceshall be shifted well beyond the edge of the driving wheel before it canbe raised through the clock-plate. The parts are re-assembled in anobvious manner by the simple reverse of the above described operations;during such assembling, the escape pinion 18 being simply shiftedlaterally into reengagement with the driving wheel 23. It will thus beseen that this construction prevents either the lifting out of thepotence from the clockplate or its replacement through the clockplate ina position where it can strike the driving wheel 23 during either ofsaid movements. In other words, it has to be fully clear of the drivingwheel before it can either be withdrawn or replaced. It is alsodesirable to arrest the movement of the clock or watch train when theescapement mechanism is withdrawn, thus preventing the train from racingand running down and thereby involving useless wear and possible injuryto the parts.

In conjunction with the improvement hereinabove described I have deviseda simple means for automatically arresting the driving wheel during theinitial operation of removing the escapement mechanism as well as forautomatically releasing the driving wheel during the final operation ofre placing the escapement mechanism. On the under side of theclock-plate 5 is pivoted at 24: an elbow lever, one arm 25 of whichextends approximately tangentially to the driving wheel 23 and is formedwith a. downwardly turned end or dog 26 adapted to engage the teeth ofthe driving wheel 23 under the impulse of a spring 27 that is housedwithin a socket 28 in the under side of the clock-plate and pressesagainst an upturned end 25' of the other arm 30 of the elbow lever. Thisup-turned end :29 bears against the locking shoulder T of the potence,as clearly shown in Fig. 3; and the relation of the parts is such that,when the potence is in its operative or working position as shown in thedrawings, it compresses the spring 27 through the contact member 29 ofthe safety stopping lever, and swings the other arm 25 of said lever tocarry the dog 26 out of engagement with the driving wheel 23. 'hen,however, the potence is slid rearwardly, as above described, preliminaryto its withdrawal from the clockplate, the spring 27 is released andthrows the safety stopping lever into instantaneous stopping em ragementwith the driving Wheel 93, thus locking the train against movement. Itwill thus be seen that the action of the safety stopping lever isentirely automatic both during the withdrawal of the potenoe and itsreplacement.

I claim 1. The combination with the escapement driving wheel, of aclock-plate having a slot, and a bodily removable escapement mechanismincluding a potence extending through said slot and carrying the escapepinion, and a laterally projecting locking shoulder on the side of saidpotence toward said driving wheel engaging beneath a portion of saidclock-plate.

2. The combination with the escapement driving wheel, of a clock-platehaving a slot countersunk on its side toward the driving wheel and abodily removable escapement mechanism including a potence extendingthrough said slot and carrying the escape pinion, and a locking shoulderon said potence engaging the countersunk side of said slot.

3. The combination with the escapement driving wheel, of a clock-platehavin a slot, a bodily iemovable escapement mec anism having a potenceextending through said slot and carrying the escape pinion, a laterallyprojecting locking shoulder on the side of said potence toward saiddriv' wheel engagin beneath a portion of sai clock-plate, an a safetystopping device 00- operating with said driving wheel, said safety stoping device being moved to and held in re ease position by said potenoeand spring-actuated into locking engagement with the driving wheel.

4. The combination with the escapement driving wheel, of a clock-platehaving a slot countersunk on its side toward the driving wheel, a bodilyremovable escapement mechanism including a potenoe extending throughsaid slot and carrying the escape pinion, a locking shoulder on saidotenoe engaging the countersunk side of said slot, and a safety stoppingdevice cooperating with said driving wheel, said safety stopping devicebeing moved to and held in release position by said potence, and sprinactuated into locking engagement with e drivin wheel.

T e combination with tho escapement driving wheel, of a clock-platehaving a slot countersunk on its side toward the driving wheel, a bodilremovable escapement mechanism inclur ing a potence extending throughsaid slot and carrying the escape pinion, a locking shoulder on saidpotenoo engaging the countersunk side of said slot, and a safetystopping device comprising a pivoted lever carrying a dog adopted toengage the teeth of the driving wheel and a spring normally urging saidlever into looking position, said lever engaging the potenco andnormally held by the latter in release position against the action ofsaid FRED H. CORT EL \Vitnesses:

SAMUEL N. Pom), Jorcn M. Lo'rz.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Paton,

Washington, D. O.

